ORCID Profile
0000-0003-2293-9185
Current Organisations
University of Bristol
,
University of Western Australia
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Publisher: The Royal Society
Date: 19-09-2018
Abstract: In recent decades, a number of studies have examined whether various non-human animals understand their partner's role in cooperative situations. Yet the relatively tolerant timing requirements of these tasks make it theoretically possible for animals to succeed by using simple behavioural strategies rather than by jointly intended coordination. Here we investigated whether bottlenose dolphins could understand a cooperative partner's role by testing whether they could learn a button-pressing task requiring precise behavioural synchronization. Specifically, members of cooperative dyads were required to swim across a lagoon and each press their own underwater button simultaneously (within a 1 s time window), whether sent together or with a delay between partners of 1–20 s. We found that dolphins were able to work together with extreme precision even when they had to wait for their partner, and that their coordination improved over the course of the study, with the time between button presses in the latter trials averaging 370 ms. These findings show that bottlenose dolphins can learn to understand their partner's role in a cooperative situation, and suggest that the behavioural synchronization evident in wild dolphins' synchronous movement and coordinated alliance displays may be a generalized cognitive ability that can also be used to solve novel cooperative tasks.
Publisher: Proceedings of the National Academy of Sciences
Date: 29-08-2022
Abstract: Efforts to understand human social evolution rely largely on comparisons with nonhuman primates. However, a population of bottlenose dolphins in Shark Bay, Western Australia, combines a chimpanzee-like fission-fusion grouping pattern, mating system, and life history with the only nonhuman ex le of strategic multilevel male alliances. Unrelated male dolphins form three alliance levels, or “orders”, in competition over females: both within-group alliances (i.e., first- and second-order) and between-group alliances (third-order), based on cooperation between two or more second-order alliances against other groups. Both sexes navigate an open society with a continuous mosaic of overlapping home ranges. Here, we use comprehensive association and consortship data to examine fine-scale alliance relationships among 121 adult males. This analysis reveals the largest nonhuman alliance network known, with highly differentiated relationships among in iduals. Each male is connected, directly or indirectly, to every other male, including direct connections with adult males outside of their three-level alliance network. We further show that the duration with which males consort females is dependent upon being well connected with third-order allies, independently of the effect of their second-order alliance connections, i.e., alliances between groups increase access to a contested resource, thereby increasing reproductive success. Models of human social evolution traditionally link intergroup alliances to other ergent human traits, such as pair bonds, but our study reveals that intergroup male alliances can arise directly from a chimpanzee-like, promiscuous mating system without one-male units, pair bonds, or male parental care.
Publisher: The Royal Society
Date: 12-06-2019
Abstract: Homophilous behaviour plays a central role in the formation of human friendships. In iduals form social ties with others that show similar phenotypic traits, independently of relatedness. Evidence of such homophily can be found in bottlenose dolphins ( Tursiops aduncus ) in Shark Bay, Western Australia, where females that use marine sponges as foraging tools often associate with other females that use sponges. ‘Sponging’ is a socially learned, time-consuming behaviour, transmitted from mother to calf. Previous research illustrated a strong female bias in adopting this technique. The lower propensity for males to engage in sponging may be due to its incompatibility with adult male-specific behaviours, particularly the formation of multi-level alliances. However, the link between sponging and male behaviour has never been formally tested. Here, we show that male spongers associated significantly more often with other male spongers irrespective of their level of relatedness. Male spongers spent significantly more time foraging, and less time resting and travelling, than did male non-spongers. Interestingly, we found no difference in time spent socializing. Our study provides novel insights into the relationship between tool use and activity budgets of male dolphins, and indicates social homophily in the second-order alliance composition of tool-using bottlenose dolphins.
Publisher: The Royal Society
Date: 07-2019
Abstract: Behavioural differences among social groups can arise from differing ecological conditions, genetic predispositions and/or social learning. In the past, social learning has typically been inferred as responsible for the spread of behaviour by the exclusion of ecological and genetic factors. This ‘method of exclusion’ was used to infer that ‘sponging’, a foraging behaviour involving tool use in the bottlenose dolphin ( Tursiops aduncus ) population in Shark Bay, Western Australia, was socially transmitted. However, previous studies were limited in that they never fully accounted for alternative factors, and that social learning, ecology and genetics are not mutually exclusive in causing behavioural variation. Here, we quantified the importance of social learning on the diffusion of sponging, for the first time explicitly accounting for ecological and genetic factors, using a multi-network version of ‘network-based diffusion analysis'. Our results provide compelling support for previous findings that sponging is vertically socially transmitted from mother to (primarily female) offspring. This research illustrates the utility of social network analysis in elucidating the explanatory mechanisms behind the transmission of behaviour in wild animal populations.
Publisher: The Royal Society
Date: 22-04-2013
Abstract: Vocal learning is relatively common in birds but less so in mammals. Sexual selection and in idual or group recognition have been identified as major forces in its evolution. While important in the development of vocal displays, vocal learning also allows signal copying in social interactions. Such copying can function in addressing or labelling selected conspecifics. Most ex les of addressing in non-humans come from bird song, where matching occurs in an aggressive context. However, in other animals, addressing with learned signals is very much an affiliative signal. We studied the function of vocal copying in a mammal that shows vocal learning as well as complex cognitive and social behaviour, the bottlenose dolphin ( Tursiops truncatus ). Copying occurred almost exclusively between close associates such as mother–calf pairs and male alliances during separation and was not followed by aggression. All copies were clearly recognizable as such because copiers consistently modified some acoustic parameters of a signal when copying it. We found no evidence for the use of copying in aggression or deception. This use of vocal copying is similar to its use in human language, where the maintenance of social bonds appears to be more important than the immediate defence of resources.
Publisher: Wiley
Date: 30-06-2015
Publisher: The Royal Society
Date: 03-2021
DOI: 10.1098/RSOS.202073
Abstract: Cooperation experiments have long been used to explore the cognition underlying animals' coordination towards a shared goal. While the ability to understand the need for a partner in a cooperative task has been demonstrated in a number of species, there has been far less focus on cooperation experiments that address the role of communication. In humans, cooperative efforts can be enhanced by physical synchrony, and coordination problems can be solved using spoken language. Indeed, human children adapt to complex coordination problems by communicating with vocal signals. Here, we investigate whether bottlenose dolphins can use vocal signals to coordinate their behaviour in a cooperative button-pressing task. The two dolphin dyads used in this study were significantly more likely to cooperate successfully when they used whistles prior to pressing their buttons, with whistling leading to shorter button press intervals and more successful trials. Whistle timing was important as the dolphins were significantly more likely to succeed if they pushed their buttons together after the last whistle, rather than pushing independently of whistle production. Bottlenose dolphins are well known for cooperating extensively in the wild, and while it remains to be seen how wild dolphins use communication to coordinate cooperation, our results reveal that at least some dolphins are capable of using vocal signals to facilitate the successful execution of coordinated, cooperative actions.
Publisher: Proceedings of the National Academy of Sciences
Date: 22-07-2013
Abstract: In animal communication research, vocal labeling refers to incidents in which an animal consistently uses a specific acoustic signal when presented with a specific object or class of objects. Labeling with learned signals is a foundation of human language but is notably rare in nonhuman communication systems. In natural animal systems, labeling often occurs with signals that are not influenced by learning, such as in alarm and food calling. There is a suggestion, however, that some species use learned signals to label conspecific in iduals in their own communication system when mimicking in idually distinctive calls. Bottlenose dolphins ( Tursiops truncatus ) are a promising animal for exploration in this area because they are capable of vocal production learning and can learn to use arbitrary signals to report the presence or absence of objects. Bottlenose dolphins develop their own unique identity signal, the signature whistle. This whistle encodes in idual identity independently of voice features. The copying of signature whistles may therefore allow animals to label or address one another. Here, we show that wild bottlenose dolphins respond to hearing a copy of their own signature whistle by calling back. Animals did not respond to whistles that were not their own signature. This study provides compelling evidence that a dolphin’s learned identity signal is used as a label when addressing conspecifics. Bottlenose dolphins therefore appear to be unique as nonhuman mammals to use learned signals as in idually specific labels for different social companions in their own natural communication system.
Publisher: MDPI AG
Date: 28-04-2022
Abstract: Oral submucous fibrosis (OSMF) is a chronic oral potentially malignant disorder (OPMD). It is described as a scarring disease of the oral mucosa associated with excess oxidants and insufficient antioxidants. While it is becoming increasingly accepted that oxidative stress results in excessive accumulation of collagen and progressive fibrosis of the submucosal tissues, there is limited data regarding the moderation of oxidative stress to initiate or prevent OSMF. To assess the scope for mechanism-based approaches to prevent or reverse OSMF, we systematically evaluated the existing literature and investigated the role of oxidative stress in the pathogenesis and chemoprevention of OSMF. A search for relevant articles on PubMed and Scopus was undertaken using pre-defined inclusion and exclusion criteria. A total of 78 articles were selected in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. The articles eligible for assessment investigated both OSMF and/or oxidative stress biomarkers or specific antioxidants. Both in vitro and human studies consistently demonstrated variations in oxidative stress biomarker levels in OSMF and revealed an increase in oxidative stress, paralleling the development of the disease. Furthermore, the use of antioxidant supplements was overall associated with an improvement in clinical outcomes. Having identified the significance of oxidative stress in OSMF and the therapeutic potential of antioxidant supplements, this scoping review highlights the need for further well-designed studies in the development of mechanism-based interventions for managing OSMF.
Publisher: Springer Science and Business Media LLC
Date: 17-02-2015
DOI: 10.1007/S10071-015-0851-7
Abstract: Food-related signalling is widespread in the animal kingdom with some food-associated vocalizations considered functionally referential. Food calls can, however, vary greatly in the type of information they convey. Thus, there are a multitude of purposes for which food calls are used, including social recruitment, caller spacing, the indication of type, quantity, quality, isibility of food, the caller's hunger level and even as tools to manipulate prey behaviour. Yet little work has focused on the social aspect of food calling in animals. We investigated the association of social signals in wild bottlenose dolphins with foraging behaviour where context-specific food-associated calls are commonly produced. Our data showed that specific social signals were significantly correlated with food call production and these calls rarely occurred in the absence of food calls. We suggest that animals are sharing additional information on the food patch itself with their social affiliates.
Publisher: Wiley
Date: 11-07-2022
Abstract: Cetaceans represent an evolutionary peak in terms of their cognitive capacities, complex communication systems and their structured, multilevel societies. However, the difficulty of observing their behaviour underwater means that studying whale and dolphin sociality in the wild poses some significant methodological challenges. Traditionally, playback experiments have been used to explore aspects of communication and cognition in whales and dolphins, particularly with trained animals under human care. However, while these studies have provided major breakthroughs in our understanding of cetacean social cognition, it is difficult to know whether these findings generalize to wild animals. In recent years, new state‐of‐the‐art technology (drones and non‐invasive sound and movement tags) have revolutionized the field of marine mammal behaviour, providing unparalleled information on the fine‐scale behaviour of in iduals in the wild. Here, we review the state of the field, combining published studies with our own extensive experience, to demonstrate how these new technologies fundamentally change the behavioural metrics that we are able to measure allowing us to move from categorical observations to quantifying fine‐scale changes in movement, activity and vocal behaviour. We discuss how conducting playback experiments alongside these new technologies combines rigorous experimental design with strong ecological validity and increased reproducibility and can be adapted for many social species, setting the standard for high‐calibre, field‐based experiments that explore animal social cognition in the wild.
Publisher: MDPI AG
Date: 29-06-2020
DOI: 10.3390/ANI10071118
Abstract: Reliable scientific knowledge is crucial for informing legislative, regulatory, and policy decisions in a variety of areas. To that end, scientific reviews of topical issues can be invaluable tools for informing productive discourse and decision-making, assuming these reviews represent the target body of scientific knowledge as completely, accurately, and objectively as possible. Unfortunately, not all reviews live up to this standard. As a case in point, Marino et al.’s review regarding the welfare of killer whales in captivity contains methodological flaws and misrepresentations of the scientific literature, including problematic referencing, overinterpretation of the data, misleading word choice, and biased argumentation. These errors and misrepresentations undermine the authors’ conclusions and make it impossible to determine the true state of knowledge of the relevant issues. To achieve the goal of properly informing public discourse and policy on this and other issues, it is imperative that scientists and science communicators strive for higher standards of analysis, argumentation, and objectivity, in order to clearly communicate what is known, what is not known, what conclusions are supported by the data, and where we are lacking the data necessary to draw reliable conclusions.
Publisher: Elsevier BV
Date: 12-2022
DOI: 10.1016/J.TINS.2022.09.006
Abstract: Bottlenose dolphins are highly social, renowned for their vocal flexibility, and possess highly enlarged brains relative to their body size. Here, we discuss some of the defining features of bottlenose dolphin social and vocal complexity and place this in the context of their cognitive evolution.
Publisher: Elsevier BV
Date: 04-2022
DOI: 10.1016/J.CUB.2022.02.019
Abstract: Vocal interactions are intrinsic features of social groups and can play a pivotal role in social bonding.
Publisher: The Royal Society
Date: 10-2016
Abstract: Over the years, vocal matching has progressed beyond being an interesting behavioural phenomenon to one that now has relevance to a wide range of fields. In this review, we use birds and cetaceans to explain what vocal matching is, why animals vocally match and how vocal matching can be identified. We show that while the functional aspects of vocal matching are similar, the contexts in which matching is used can differ between taxa. Whereas vocal matching in songbirds facilitates mate attraction and the immediate defence of resources, in parrots and cetaceans it plays a role in the maintenance of social bonds and the promotion of behavioural synchrony. We propose criteria for defining vocal matching with the aim of stimulating more matching studies across a wider range of taxa, including those using other, non-vocal, communication modalities. Finally, we encourage future studies to explore the importance of vocal learning in the development of vocal matching, and the information it may provide to third parties in the communication network.
Publisher: Springer Science and Business Media LLC
Date: 25-03-2021
DOI: 10.1038/S41598-021-85583-X
Abstract: Investigations into cooperative partner choice should consider both potential and realised partners, allowing for the comparison of traits across all those available. Male bottlenose dolphins form persisting multi-level alliances. Second-order alliances of 4–14 males are the core social unit, within which 2–3 males form first-order alliances to sequester females during consortships. We compared social bond strength, relatedness and age similarity of potential and realised partners of in idual males in two age periods: (i) adolescence, when second-order alliances are formed from all available associates, and (ii) adulthood, when first-order allies are selected from within second-order alliances. Social bond strength during adolescence predicted second-order alliance membership in adulthood. Moreover, males preferred same-aged or older males as second-order allies. Within second-order alliances, non-mating season social bond strength predicted first-order partner preferences during mating season consortships. Relatedness did not influence partner choice on either alliance level. There is thus a striking resemblance between male dolphins, chimpanzees and humans, where closely bonded non-relatives engage in higher-level, polyadic cooperative acts. To that end, our study extends the scope of taxa in which social bonds rather than kinship explain cooperation, providing the first evidence that such traits might have evolved independently in marine and terrestrial realms.
Publisher: Elsevier BV
Date: 06-2018
DOI: 10.1016/J.CUB.2018.05.013
Abstract: Cooperation between allied in iduals and groups is ubiquitous in human societies, and vocal communication is known to play a key role in facilitating such complex human behaviors [1, 2]. In fact, complex communication may be a feature of the kind of social cognition required for the formation of social alliances, facilitating both partner choice and the execution of coordinated behaviors [3]. As such, a compelling avenue for investigation is what role flexible communication systems play in the formation and maintenance of cooperative partnerships in other alliance-forming animals. Male bottlenose dolphins in some populations form complex multi-level alliances, where in iduals cooperate in the pursuit and defense of an important resource: access to females [4]. These strong relationships can last for decades and are critical to each male's reproductive success [4]. Convergent vocal accommodation is used to signal social proximity to a partner or social group in many taxa [5, 6], and it has long been thought that allied male dolphins also converge onto a shared signal to broadcast alliance identity [5-8]. Here, we combine a decade of data on social interactions with dyadic relatedness estimates to show that male dolphins that form multi-level alliances in an open social network retain in idual vocal labels that are distinct from those of their allies. Our results differ from earlier reports of signature whistle convergence among males that form stable alliance pairs. Instead, they suggest that in idual vocal labels play a central role in the maintenance of differentiated relationships within complex nested alliances.
Publisher: The Royal Society
Date: 07-2015
Abstract: Over the years, playback experiments have helped further our understanding of the wonderful world of animal communication. They have provided fundamental insights into animal behaviour and the function of communicative signals in numerous taxa. As important as these experiments are, however, there is strong evidence to suggest that the information conveyed in a signal may only have value when presented interactively. By their very nature, signalling exchanges are interactive and therefore, an interactive playback design is a powerful tool for examining the function of such exchanges. While researchers working on frog and songbird vocal interactions have long ch ioned interactive playback, it remains surprisingly underused across other taxa. The interactive playback approach is not limited to studies of acoustic signalling, but can be applied to other sensory modalities, including visual, chemical and electrical communication. Here, I discuss interactive playback as a potent yet underused technique in the field of animal behaviour. I present a concise review of studies that have used interactive playback thus far, describe how it can be applied, and discuss its limitations and challenges. My hope is that this review will result in more scientists applying this innovative technique to their own study subjects, as a means of furthering our understanding of the function of signalling interactions in animal communication systems.
Publisher: The Royal Society
Date: 04-2020
Abstract: Synchronous displays are hallmarks of many animal societies, ranging from the pulsing flashes of fireflies, to military marching in humans. Such displays are known to facilitate mate attraction or signal relationship quality. Across many taxa, synchronous male displays appear to be driven by competition, while synchronous displays in humans are thought to be unique in that they serve a cooperative function. Indeed, it is well established that human synchrony promotes cooperative endeavours and increases success in joint action tasks. We examine another system in which synchrony is tightly linked to cooperative behaviour. Male bottlenose dolphins form long-lasting, multi-level, cooperative alliances in which they engage in coordinated efforts to coerce single oestrus females. Previous work has revealed the importance of motor synchrony in dolphin alliance behaviour. Here, we demonstrate that allied dolphins also engage in acoustic coordination whereby males will actively match the tempo and, in some cases, synchronize the production of their threat vocalization when coercing females. This finding demonstrates that male dolphins are capable of acoustic coordination in a cooperative context and, moreover, suggests that both motor and acoustic coordination are features of coalitionary behaviour that are not limited to humans.
Publisher: Springer Science and Business Media LLC
Date: 20-10-2017
DOI: 10.1038/S41598-017-13898-9
Abstract: Sexual displays enriched by object carrying serve to increase in idual male fitness, yet are uncommon phenomena in the animal kingdom. While they have been documented in a variety of taxa, primarily birds, they are rare outside non-human mammals. Here, we document marine sponge presenting associated with visual and acoustic posturing found in several, geographically widespread populations of Australian humpback dolphins ( Sousa sahulensis ) over ten years of observation. Only adult males presented marine sponges, typically doing so in the presence of sexually mature females, although social groups predominantly consisted of mixed age and sex classes. Male humpback dolphins appear to be using sponges for signalling purposes in multi-modal sexual displays. Further, based on limited behavioural and genetic data, we hypothesise that pairs of adult male Sousa form at least temporary coalitions or alliances. The use of objects in sexual displays by non-human mammals is rare and, moreover, cooperation between males in the pursuit of an in isible resource is an evolutionary hurdle relatively few species have overcome. These findings suggest a hitherto unrecognised level of social complexity in humpback dolphins.
Publisher: Elsevier BV
Date: 04-2022
DOI: 10.1016/J.CUB.2022.03.027
Abstract: Understanding determinants of differential reproductive success is at the core of evolutionary biology because of its connection to fitness. Early work has linked variation in reproductive success to differences in age,
Publisher: Springer Science and Business Media LLC
Date: 22-04-2021
DOI: 10.1038/S41467-021-22668-1
Abstract: In Shark Bay, Western Australia, male bottlenose dolphins form a complex nested alliance hierarchy. At the first level, pairs or trios of unrelated males cooperate to herd in idual females. Multiple first-order alliances cooperate in teams (second-order alliances) in the pursuit and defence of females, and multiple teams also work together (third-order alliances). Yet it remains unknown how dolphins classify these nested alliance relationships. We use 30 years of behavioural data combined with 40 contemporary sound playback experiments to 14 allied males, recording responses with drone-mounted video and a hydrophone array. We show that males form a first-person social concept of cooperative team membership at the second-order alliance level, independently of first-order alliance history and current relationship strength across all three alliance levels. Such associative concepts develop through experience and likely played an important role in the cooperative behaviour of early humans. These results provide evidence that cooperation-based concepts are not unique to humans, occurring in other animal societies with extensive cooperation between non-kin.
Publisher: Elsevier BV
Date: 02-2023
Publisher: Wiley
Date: 15-04-2016
DOI: 10.1111/MMS.12317
Publisher: Wiley
Date: 15-12-2022
DOI: 10.1111/EVA.13516
Abstract: Knowledge of an animal's chronological age is crucial for understanding and predicting population demographics, survival and reproduction, but accurate age determination for many wild animals remains challenging. Previous methods to estimate age require invasive procedures, such as tooth extraction to analyse growth layers, which are difficult to carry out with large, mobile animals such as cetaceans. However, recent advances in epigenetic methods have opened new avenues for precise age determination. These ‘epigenetic clocks’ present a less invasive alternative and can provide age estimates with unprecedented accuracy. Here, we present a species‐specific epigenetic clock based on skin tissue s les for a population of Indo‐Pacific bottlenose dolphins ( Tursiops aduncus ) in Shark Bay, Western Australia. We measured methylation levels at 37,492 cytosine‐guanine sites (CpG sites) in 165 s les using the mammalian methylation array. Chronological age estimates with an accuracy of ±1 year were available for 68 animals as part of a long‐term behavioral study of this population. Using these s les with known age, we built an elastic net model with Leave‐One‐Out‐Cross‐Validation, which retained 43 CpG sites, providing an r = 0.86 and median absolute age error (MAE) = 2.1 years (5% of maximum age). This model was more accurate for our data than the previously published methylation clock based on skin s les of common bottlenose dolphins ( T. truncatus : r = 0.83, MAE = 2.2) and the multi‐species odontocete methylation clock ( r = 0.68, MAE = 6.8), highlighting that species‐specific clocks can have superior performance over those of multi‐species assemblages. We further developed an epigenetic sex estimator, predicting sex with 100% accuracy. As age and sex are critical parameters for the study of animal populations, this clock and sex estimator will provide a useful tool for extracting life history information from skin s les rather than long‐term observational data for free‐ranging Indo‐Pacific bottlenose dolphins worldwide.
Publisher: Springer New York
Date: 2016
DOI: 10.1007/978-1-4939-2981-8_49
Abstract: Loud anthropogenic underwater noise, such as that associated with sonar operations, pile driving, or seismic surveys, can cause behavioral and physiological disturbance to many animals that may affect their survival or ability to breed. However, no formal framework for assessing the population-level consequences of this disturbance is currently available. We describe an interim version of a framework developed by a working group on the population consequences of disturbance, funded by the US Office of Naval Research through the University of California, that can be used to assess the effects of offshore renewable energy developments on marine mammal populations.
Publisher: Springer New York
Date: 2016
DOI: 10.1007/978-1-4939-2981-8_27
Abstract: There are many developments for offshore renewable energy around the United Kingdom whose installation typically produces large amounts of far-reaching noise, potentially disturbing many marine mammals. The potential to affect the favorable conservation status of many species means extensive environmental impact assessment requirements for the licensing of such installation activities. Quantification of such complex risk problems is difficult and much of the key information is not readily available. Expert elicitation methods can be employed in such pressing cases. We describe the methodology used in an expert elicitation study conducted in the United Kingdom for combining expert opinions based on statistical distributions and copula-like methods.
Publisher: Elsevier BV
Date: 08-2022
DOI: 10.1016/J.BEPROC.2022.104691
Abstract: A ision of labor with role specialization is defined as in iduals specializing in a subtask during repetitions of a group task. While this behavior is ubiquitous among humans, there are only four candidates found among non-eusocial mammals: lions, mice, chimpanzees, and bottlenose dolphins. Bottlenose dolphins in the Cedar Keys, Florida, engage in role specialized "driver-barrier feeding", where a "driver" dolphin herds mullet towards "barrier" dolphins. Thus trapped, the mullet leap out of the water where the dolphins catch them in air. To investigate whether dolphins use acoustic cues or signals to coordinate this behavior, vocalizations were recorded before and during driver-barrier feeding. Results of fine-scale audio and video analysis during 81 events by 7 different driver in iduals suggest that barrier animals coordinate movements during these events by cueing on the driver's echolocation. Analysis of dolphin whistle occurrence before driving events versus another foraging technique, which does not involve role specialization, revealed significantly higher whistle production immediately prior to driver-barrier events. Possible whistle functions include signaling motivation, recruiting in iduals to participate, and/or behavioral coordination. While the use of cues and signals is common in humans completing role-specialized tasks, this is the first study to investigate the use of vocalizations in the coordination of a role-specialized behavior in a non-human mammal.
Publisher: Springer Science and Business Media LLC
Date: 30-06-2023
DOI: 10.1007/S10071-023-01804-Y
Abstract: The social intelligence hypothesis holds that complex social relationships are the major selective force underlying the evolution of large brain size and intelligence. Complex social relationships are exemplified by coalitions and alliances that are mediated by affiliative behavior, resulting in differentiated but shifting relationships. Male Indo-Pacific bottlenose dolphins in Shark Bay, Australia, form three alliance levels or ‘orders’, primarily among non-relatives. Strategic alliance formation has been documented within both first- and second-order alliances and between second-order alliances (‘third-order alliances’), revealing that the formation of strategic inter-group alliances is not limited to humans. Here we conducted a fine-scale study on 22 adult males over a 6-year period to determine if third-order alliance relationships are differentiated, and mediated by affiliative interactions. We found third-order alliance relationships were strongly differentiated, with key in iduals playing a disproportionate role in maintaining alliances. Nonetheless, affiliative interactions occurred broadly between third-order allies, indicating males maintain bonds with third-order allies of varying strength. We also documented a shift in relationships and formation of a new third-order alliance. These findings further our understanding of dolphin alliance dynamics and provide evidence that strategic alliance formation is found in all three alliance levels, a phenomenon with no peer among non-human animals.
Publisher: Oxford University Press (OUP)
Date: 28-11-2019
Abstract: Male alliances are an intriguing phenomenon in the context of reproduction since, in most taxa, males compete over an in isible resource, female fertilization. Adult male bottlenose dolphins (Tursiops aduncus) in Shark Bay, Western Australia, form long-term, multilevel alliances to sequester estrus females. These alliances are therefore critical to male reproductive success. Yet, the long-term processes leading to the formation of such complex social bonds are still poorly understood. To identify the criteria by which male dolphins form social bonds with other males, we adopted a long-term approach by investigating the ontogeny of alliance formation. We followed the in idual careers of 59 males for 14 years while they transitioned from adolescence (8–14 years of age) to adulthood (15–21 years old). Analyzing their genetic relationships and social associations in both age groups, we found that the vast majority of social bonds present in adolescence persisted through time. Male associations in early life predict alliance partners as adults. Kinship patterns explained associations during adolescence but not during adulthood. Instead, adult males associated with males of similar age. Our findings suggest that social bonds among peers, rather than kinship, play a central role in the development of adult male polyadic cooperation in dolphins.
Publisher: Springer Science and Business Media LLC
Date: 31-08-2016
DOI: 10.1007/S10071-016-1026-X
Abstract: Two recent papers by Kuczaj et al. (Anim Cognit 18:543-550, 2015) and Eskelinen et al. (Anim Cognit 19:789-797, 2016) claim to have demonstrated that (i) bottlenose dolphins (Tursiops truncatus) cooperated to solve a novel task and (ii) vocal signals were important for coordinating these cooperative efforts. Although it is likely that bottlenose dolphins may share communicative signals in order to achieve a common goal, we suggest that this has not been demonstrated in the aforementioned studies. Here, we discuss the two main problems that preclude any definitive conclusions being drawn on cooperative task success and vocal communication from these studies. The first lies in the experimental design. The 'cooperative task', involving an apparatus that requires two dolphins to pull in opposite directions in order to achieve a food reward, is not conducive to cooperation, but could instead reflect a competitive 'tug-of-war'. It is therefore of questionable use in distinguishing competitive from cooperative interactions. Second, the suggestion that the occurrence of burst-pulsed signals in this task was indicative of cooperation is disputable, as (i) this study could not determine which dolphins were actually producing the signals and (ii) this sound type is more commonly associated with aggressive signalling in dolphins. We commend the authors for investigating this exciting and topical area in animal communication and cognition, but the question of whether dolphins cooperate and communicate to solve a cooperative task remains as yet unanswered.
Publisher: Elsevier BV
Date: 05-2016
DOI: 10.1016/J.BEPROC.2016.03.005
Abstract: In idual vocal signatures play an important role in parent-offspring recognition in many animals. One species that uses signature calls to accurately facilitate in idual recognition is the bottlenose dolphin. Female dolphins and their calves will use their highly in idualised signature whistles to identify and maintain contact with one another. Previous studies have shown high signature whistle rates of both mothers and calves during forced separations. In more natural settings, it appears that the calf vocalises more frequently to initiate reunions with its mother. However, little is known about the mechanisms a female dolphin may employ when there is strong motivation for her to reunite with her calf. In this study, we conducted a series of experimental trials in which we asked a female dolphin to retrieve either her wandering calf or a series of inanimate objects (control). Our results show that she used her vocal signature to actively recruit her calf, and produced no such signal when asked to retrieve the objects. This is the first study to clearly manipulate a dolphin's motivation to retrieve her calf with experimental controls. The results highlight that signature whistles are not only used in broadcasting in idual identity, but that maternal signature whistle use is important in facilitating mother-calf reunions.
Publisher: Springer Science and Business Media LLC
Date: 08-2022
DOI: 10.1007/S42991-022-00259-X
Abstract: Social structuring from assortative associations may affect in idual fitness, as well as population-level processes. Gaining a broader understanding of social structure can improve our knowledge of social evolution and inform wildlife conservation. We investigated association patterns and community structure of female Indo-Pacific bottlenose dolphins ( Tursiops aduncus ) in Shark Bay, Western Australia, assessing the role of kinship, shared culturally transmitted foraging techniques, and habitat similarity based on water depth. Our results indicated that associations are influenced by a combination of uni- and biparental relatedness, cultural behaviour and habitat similarity, as these were positively correlated with a measure of dyadic association. These findings were matched in a community level analysis. Members of the same communities overwhelmingly shared the same habitat and foraging techniques, demonstrating a strong homophilic tendency. Both uni- and biparental relatedness between dyads were higher within than between communities. Our results illustrate that intraspecific variation in sociality in bottlenose dolphins is influenced by a complex combination of genetic, cultural, and environmental aspects.
Publisher: Wiley
Date: 19-03-2012
Publisher: Informa UK Limited
Date: 25-04-2016
Publisher: Springer Science and Business Media LLC
Date: 17-07-2019
Publisher: Elsevier BV
Date: 10-2014
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Stephanie King.